Bores drilled to access subsurface hydrocarbon reservoirs are lined with metal tubing to inter alia prevent-collapse of the bore walls and to provide pressure integrity. The characteristics of the bore-lining tubing utilised to line a bore will be based on a number of factors, one being the collapse or crush-resistance of the tubing. This is the ability of the tubing to withstand external radial forces, as may result from fluid pressure or from mechanical forces applied by a surrounding rock formation. The collapse resistance of a section of tubing may be estimated by means of calculations, typically following an American Petroleum Institute (API) standard formulation (API Bulletin 5C3). Alternatively, a section of tubing with its ends blanked off may be immersed in hydraulic fluid which is then pressurised until the tubing collapses.